Radio frequency device and mobile communication terminal using the same

• US 8,023,995 B2
• Filed: 01/05/2005
• Issued: 09/20/2011
• Est. Priority Date: 03/31/2004
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Kuriyama, Akira, Yamawaki, Taizo, Tanaka, Satoshi
• Primary Examiner(s): Eng; George
• Assistant Examiner(s): Manoharan; Muthuswamy
• Application Number:
  US11/028,925
• Publication Number:
  US 20050221855A1
• Time in Patent Office: 2,449 Days
• Field of Search: 455/552.1, 455/553.1
• US Class Current: 455/553.1
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths

Abstract

There is provided a radio frequency circuit device for multi-band and multi-mode which is low in a circuit loss, and a mobile communication terminal using the radio frequency circuit device. The radio frequency circuit device has a first path 110 that includes an amplifier 10a that amplifies signals of at least two modulation techniques in power, a matching network 20 that is connected to the amplifier and a duplexer 50 and allows the matching network to be coupled with an antenna, and a second path 111 that does not include the duplexer and allows the matching network to be coupled with the antenna. The first path is selected when the amplifier amplifies one of the signals of at least two modulation techniques, and the second path is selected when the amplifier amplifies another signal. An output impedance of the amplifier is matched with an impedance when viewing the antenna side from the amplifier in the first path and the second path.

Claims

1. A radio frequency device, comprising:

a first amplifier that amplifies a first signal of a first modulation technique in power;

a second amplifier that amplifies a second signal of a second modulation technique in power;

a first matching network that is connected to an output terminal of the first amplifier;

a second matching network that is connected to an output terminal of the second amplifier;

a third matching network that is connected to both an output terminal of the first matching network and an output terminal of the second matching network

a first path that includes a duplexer between the third matching network and an antenna, and allows the first amplifier to be coupled with the antenna through the first and third matching networks and the duplexer; and

a second path that does not include the duplexer and allows the second amplifier to be coupled with the antenna through the second and third matching networks,

wherein the first path is selected when the first amplifier amplifies the first signal, and the second path is selected when the second amplifier amplifies the second signal,

wherein a first terminal of a switch through which the third matching network and the duplexer are electrically connected has a first impedance when the first path is selected, said first impedance being dependent on an impedance of said duplexer,

wherein a second terminal of the switch at which the third matching network and the antenna are electrically connected has a second impedance when the second path is selected, said second impedance being dependent on an impedance of said switch,

wherein the first impedance is different from the second impedance,

wherein the first path has a third impedance when viewing the antenna side from the output terminal of the first amplifier,

wherein the second path has a fourth impedance when viewing the antenna side from the output terminal of the second amplifier,

wherein the third impedance is different from the fourth impedance, and

wherein the first amplifier amplifies the first signal on the third impedance, and the second amplifier amplifies the second signal on the fourth impedance.

2. The radio frequency circuit device according to claim 1, wherein the switch operates to select between the first path and the second path (switch in FIG. 6).

3. A radio frequency circuit device, comprising:

a first amplifier that amplifies a first transmitter signal of a first modulation technique in power;

a second amplifier that amplifies a second transmitter signal of a second modulation technique in power;

a first matching network that is connected to an output terminal of the first amplifier;

a second matching network that is connected to an output terminal of the second amplifier;

a third matching network that is connected to both an output terminal of the first matching network and an output terminal of the second matching network;

a first path that includes a duplexer between the third matching network and an antenna, and that allows the first amplifier to be coupled with the antenna through the first and third matching networks and the duplexer; and

a second path that does not include the duplexer and that allows the second amplifier to be coupled with the antenna through the second and third matching networks;

wherein the first path is selected when the first amplifier amplifies the first transmitter signal, and the second path is selected when the second amplifier amplifies the second transmitter signal,

wherein a first terminal of a switch through which the third matching network and the duplexer are electrically connected has a first impedance when the first path is selected, said first impedance being dependent on an impedance of said duplexer,

wherein a second terminal of the switch at which the third matching network and the antenna are electrically connected has a second impedance when the second path is selected, said second impedance being dependent on an impedance of said switch,

wherein the first impedance is different from the second impedance,

wherein the first path has a third impedance when viewing the antenna side from the output terminal of the first amplifier,

wherein the second path has a fourth impedance when viewing the antenna side from the output terminal of the second amplifier,

wherein the third impedance is different from the fourth impedance, and

wherein the first amplifier amplifies the first signal on the third impedance, and the second amplifier amplifies the second signal on the fourth impedance.

4. The radio frequency circuit device according to claim 3, wherein the switch operates to select between the first path and the second path.